There is if you don't have the expertise. Of course, arguably if that's the case, you shouldn't be developing such a product anyway. But as the post detailed, by switching to a Pi Zero and removing the Adafruit HAT, the BOM costs would already drop significantly. I think if you're smart about it, you absolutely can build a viable product this way. Certainly not as profitable, but possible.
Eventually I switched some things up and it got much easier.
Definitely not for scaling, but for deploying prototypes this approach is awesome! Eg use the Pi to create some prototypes, get user feedback, launch a kickstarter, do what you said. I worked at robotics startup that did this, worked super well for our first robots. Podcast about it: podcasts.apple.com/us/podcast/erik-schluntz-cobalt-robotics/id1649845905?i=1000584727151
Genuinely curious, as I've typically used things like the Pi for projects like this but have been genuinely curious what it would take to strip it down to something less powerful and achieve the same result.
https://raspberry.piaustralia.com.au/products/raspberry-pi-p...
Since I am a Go developer, I like using TinyGo with these type of boards, which means I get concurrency (goroutines) as well, although sadly Tinygo doesn't yet support the Wifi module. However, I've used other boards with Wifi, and once you're connected to WiFi you can poll APIs and do anything else you do on the internet. No OS required!
As an example of a complete, stand-alone program, I wrote a digital clock in TinyGo. (https://github.com/doctor-eval/clocky) - you plug the Pico into a 7-segment display and it operates just like an old school digital clock.
Sadly it can't (yet) connect to the internet due to missing wifi support in Tinygo, and it's running on a pre-W Pico, but you get the idea.
The cheapest you can get is about $5(Espressif assembled board), with full LED matrix controller.(that's the cost of manufacturing, though)
a full blown Linux stack is $10+
This screeches to a halt, the moment that you put into perspective. My typing this is equivalent to a few dollars, because most people here have at least $50 per hour engineers. Designing PCBs for existing modules(ex. ESP32) takes a very long time(and a lot of knowledge) and it's not just "put this chip here and have software figure it out".
Missed opportunity by this startup.
With easy to use editors (e.g. easyEDA) and cheap and fast PCB production/assembly (even for small quantities), there is no reason to use overized MCUs/mini computers like the Pi and expensive modules e.g. from Adafruit.
Also, BOM components selection is key. For the same functionality, e.g. a multiplexer there are many different chips available -often at very different price points. Availability in times of chip shortages are also key to keep an eye on.
Technically this product is very simple and the BOM costs they had were a magnitude too high. Too bad because it seemed that the market was ready and they could have become a very successful business.